4 ms·

They're incredibly important, but they shouldn't be touted as facts until there's some consensus that they are facts

krastanov 8y ago
Mathematical theorems (especially no-go theorems, one of the most powerful tools in physics) are at least as much of a fact as an experimental measurement. I can concede that a pop-sci outlet should be clear about what is an experiment and what is a mathematical theorem, but was it really not clear in this case? This is a sincere question, and I care to hear your opinion: do you believe that a reader of phys.org would need more than a glance at the article to know this is a discovery about the mathematics of general relativity, not an engineering breakthrough in the creation of a scifi-like hyperdrive?
- naasking 8y ago
  > Mathematical theorems (especially no-go theorems, one of the most powerful tools in physics) are at least as much of a fact as an experimental measurement That's an overstatement. Measurements are more important than theory. We cannot form theories without measurements, and yes theories inform our measurements, but science always begins and moves forward with measurements.
  - krastanov 8y ago
    General relativity, quantum computing, some parts of thermodynamics/information theory/statistical physics, some parts of quantum field theory, some parts of condensed matter physics are all things that started as purely mathematical statements. I am not trying to diminish the monumental importance of empirical measurements, but please do not diminish the importance of logical consistency and mathematical constraints. We can say a lot about our universe with great certainty even though in same cases making direct measurements is orders of magnitude beyond our technology.
    - dbasedweeb 8y ago
      GR was amazing, but it wasn’t well known and accepted until the first measurements confirmed it. Quantum Computing is still very much up in the air, but it’s also weird to bring it up in this context, because QM is one of the most tested theories of all time. QED In particular is tested to the most decimal places of any prediction, ever. It’s also weird to act as though GR and QM started out in a vacuum, instead of what they really were, which was based on centuries of math, theory, and experiment. Edit: Unrelated, but I see you’re a fellow Greg Egan fan, good to meet you! Planck Dive has to be one of my all time favorites.
      - krastanov 8y ago
        We are talking past each other: It is a bit contradictory to say "quantum computing is up in the air" and "QM is one of the most tested theories" as an argument against what I am saying. Yes, both are statements are true, but they are in no ways counterpoints to what I am saying, if anything they support it. QM is a well established and empirically tested theory. Quantum Computing is a purely mathematical construct that emerged from that well established theory without any experimental evidence for it, and only now, 30 years later, we are starting to have a chance to employ this purely mathematical construct in practice. Same with GR: it was a purely mathematical construct for a while until we could test it, but there were too many theory clues that it must be right. And this is not selection/survival bias: it is extremely rare for humanity to find a robust mathematical construct for which we can have a high degree of certainty that it describes the universe well. In the few cases where we have had that certainty, due to mathematical proofs in seemingly disjoint fields, we ended up being right. To push it to stuff like super strings and quantum gravity: few respected scientists would claim that their pet mathematical construct is correct, but many of them will say "the vague commonalities between all these diverse and seemingly unrelated mathematical constructs definitely point to an underlying fundamental construct".
    - naasking 8y ago
      Everything you list was formulated in response to measurements that didn't fit with existing theory, with the possible exception of quantum computing. I'm not diminishing the value of theory, merely correcting what I think was an overstatement of its importance on your part.
mikekchar 8y ago
I think the key here is the word "fact". Scientific models are models. They are good models if they correspond with measurements that we make in the real world. The are even better models if they make a prediction that we can test in the real world. However, a model is never a "fact". "The FSM did it" is always going to be a possibility, even if it is an incredibly remote one. We use scientific models because they are useful not because they are fact. Even if our model does not always match our observations it can still be a useful model in some circumstances. It's very important when talking about science that we understand that it isn't fact. It is a model. It might be a good model. It might be a bad model. It might be a useful model for our application. It might be a poor model for our application. That's it. When you see a headline that says "X is Y" and it's about a scientific model, what that means is "If our model is consistent with the real world then the model predicts that we should find that X appears to be Y in the real world". But that's a bit too long to put in a headline and you would have to do it for every scientific conversation. It is extremely unfortunate that on the first day of junior high school when you start doing "proper" science classes that they don't sit people down and explain what a scientific model is. Mostly I think it's because the teachers don't know, because their teachers never taught them.
otabdeveloper1 8y ago
Really? Facts are now subject to consensus agreement? Double-plus goodthink, comrade!

Mathematical theorems (especially no-go theorems, one of the most powerful tools in physics) are at least as much of a fact as an experimental measurement. I can concede that a pop-sci outlet should be clear about what is an experiment and what is a mathematical theorem, but was it really not clear in this case? This is a sincere question, and I care to hear your opinion: do you believe that a reader of phys.org would need more than a glance at the article to know this is a discovery about the mathematics of general relativity, not an engineering breakthrough in the creation of a scifi-like hyperdrive?

naasking 8y ago
> Mathematical theorems (especially no-go theorems, one of the most powerful tools in physics) are at least as much of a fact as an experimental measurement That's an overstatement. Measurements are more important than theory. We cannot form theories without measurements, and yes theories inform our measurements, but science always begins and moves forward with measurements.
- krastanov 8y ago
  General relativity, quantum computing, some parts of thermodynamics/information theory/statistical physics, some parts of quantum field theory, some parts of condensed matter physics are all things that started as purely mathematical statements. I am not trying to diminish the monumental importance of empirical measurements, but please do not diminish the importance of logical consistency and mathematical constraints. We can say a lot about our universe with great certainty even though in same cases making direct measurements is orders of magnitude beyond our technology.
  - dbasedweeb 8y ago
    GR was amazing, but it wasn’t well known and accepted until the first measurements confirmed it. Quantum Computing is still very much up in the air, but it’s also weird to bring it up in this context, because QM is one of the most tested theories of all time. QED In particular is tested to the most decimal places of any prediction, ever. It’s also weird to act as though GR and QM started out in a vacuum, instead of what they really were, which was based on centuries of math, theory, and experiment. Edit: Unrelated, but I see you’re a fellow Greg Egan fan, good to meet you! Planck Dive has to be one of my all time favorites.
    - krastanov 8y ago
      We are talking past each other: It is a bit contradictory to say "quantum computing is up in the air" and "QM is one of the most tested theories" as an argument against what I am saying. Yes, both are statements are true, but they are in no ways counterpoints to what I am saying, if anything they support it. QM is a well established and empirically tested theory. Quantum Computing is a purely mathematical construct that emerged from that well established theory without any experimental evidence for it, and only now, 30 years later, we are starting to have a chance to employ this purely mathematical construct in practice. Same with GR: it was a purely mathematical construct for a while until we could test it, but there were too many theory clues that it must be right. And this is not selection/survival bias: it is extremely rare for humanity to find a robust mathematical construct for which we can have a high degree of certainty that it describes the universe well. In the few cases where we have had that certainty, due to mathematical proofs in seemingly disjoint fields, we ended up being right. To push it to stuff like super strings and quantum gravity: few respected scientists would claim that their pet mathematical construct is correct, but many of them will say "the vague commonalities between all these diverse and seemingly unrelated mathematical constructs definitely point to an underlying fundamental construct".
  - naasking 8y ago
    Everything you list was formulated in response to measurements that didn't fit with existing theory, with the possible exception of quantum computing. I'm not diminishing the value of theory, merely correcting what I think was an overstatement of its importance on your part.

mikekchar 8y ago

I think the key here is the word "fact". Scientific models are models. They are good models if they correspond with measurements that we make in the real world. The are even better models if they make a prediction that we can test in the real world. However, a model is never a "fact". "The FSM did it" is always going to be a possibility, even if it is an incredibly remote one. We use scientific models because they are useful not because they are fact. Even if our model does not always match our observations it can still be a useful model in some circumstances. It's very important when talking about science that we understand that it isn't fact. It is a model. It might be a good model. It might be a bad model. It might be a useful model for our application. It might be a poor model for our application. That's it. When you see a headline that says "X is Y" and it's about a scientific model, what that means is "If our model is consistent with the real world then the model predicts that we should find that X appears to be Y in the real world". But that's a bit too long to put in a headline and you would have to do it for every scientific conversation. It is extremely unfortunate that on the first day of junior high school when you start doing "proper" science classes that they don't sit people down and explain what a scientific model is. Mostly I think it's because the teachers don't know, because their teachers never taught them.

otabdeveloper1 8y ago

Really? Facts are now subject to consensus agreement? Double-plus goodthink, comrade!